¡°We don¡¯t want to be a social network or a gaming platform¡±

There are no trolleys laden with food or colorful drinks. Forget about yoga classes and massages, too. There is just a small table with a few snacks at the entrance. Unlike so many offices in Silicon Valley, next to San Francisco Bay, there is no space here for striking a pose. The founders sit at the same tables as their employees, surrounded by graffiti in the middle of which appears the company logo: WhatsApp. But from the street you would never know. It¡¯s hard to find this building in Mountain View even with the address; the only name visible on the outside is that of a firm which makes sleeves for Apple devices. Yet we are in the heart of the valley, near the headquarters of Cisco, Google and Facebook.

What WhatsApp has are more than 200 million users. Brian Acton (born in the USA, 1972) and Jan Koum (Ukraine, 1976) are hardly typical examples of the local species of entrepreneur. They are no longer crazy kids and their motto is to steer clear of all that is inessential. Their application WhatsApp, launched in 2009, has sent the SMS to the graveyard. Every day 40 people oversee the sending of nine billion messages and the receipt of 15 billion, the second figure being higher due to group messaging.

Koum had the idea. Acton joined the project soon after. In February 2009 the first version was launched. Then it was just a status application for iPhone, which issued warning that someone was not available at that moment through a preset message: ¡°Don¡¯t call me,¡± ¡°I¡¯m sleeping,¡± or ¡°I¡¯m at work¡­¡± They saw its potential and changed course. That summer they set to work on making it into the messaging service it is today. That was when Acton left his job at Yahoo! and joined up, not just as an employee but also as an investor. The team swelled to five people at the same time as they began to charge 99 cents for the app.

At the start of 2010, they took another step forward with the arrival of Nokia and Android smartphones. The team doubled to 10, and then again at the beginning of 2011 when WhatsApp for Blackberry was launched. At times they give the impression of being a couple of game show contestants, talking sotto voce and passing the questions between them: ¡°This one¡¯s for you, it¡¯s your area.¡±

Question. How is it that a service with so many users seems so mysterious?

Jan Koum. We haven¡¯t bothered too much about our image, but rather that of our users and we¡¯re proud of that. We¡¯re a technology company.

Q. In which countries do you have the most customers?

J. K. We try not to look at a single country. We offer a global product which has to work well in Brazil, India, Germany, Russia and Canada. Countries like Brazil and India are where we are growing most because they are getting more and more smartphones.

The SMS is black and white and we want to be color television"

Q. What is your perception of Spain?

J. K. Spain is one of our most heavily used countries. We put a lot of effort into making sure our service is good there, like the translation on the app and the website.

Q. What is the next thing we will be able to send on WhatsApp?

Brian Acton. We¡¯re going to focus on enriching the experience. The example I use is color television, and the SMS is black and white. We can¡¯t reveal what we haven¡¯t released yet but we never think we¡¯re done.

Q. Some people complain they get loads of messages and alerts and it distracts them.

J. K. We¡¯re the first company where you can silence alerts. In fact, we patented that. You can mute a group or a chat. You can also put a specific tone to a person to distinguish their messages. I know that with phone conversations and messaging going on, it can get a bit chatty. But we focus a lot on making sure our application is one of scales.

Q. But isn¡¯t it invasive that you can receive a message from anyone?

J. K. This is not new for WhatsApp. If you know someone¡¯s number, you can send them an SMS. We based our system on that service when we created WhatsApp and it seemed natural.

B. A. A lot of operators do not permit you to block incoming calls or messages from a particular number. We do. That¡¯s the reason why some people have to change phone when they break up with their partner for example.

Q. Is WhatsApp free and how long will I have to pay for it?

B. A. It¡¯s not free. We believe the best business is where the customer is the user and the customer is not the product. We can hear our users and improve our product better this way. I had a very bad experience in my previous workplace and ended up very fed up with advertising. We think one dollar a year is a reasonable price and we want the iPhone business to match the Android business.

Q. Is your service viable for one dollar a year?

How can there be a free product; what makes it free? There must be a hidden cost"

B. A. Yes, we don¡¯t pay for TV or celebrity endorsements [in reference to Line.] We rely on our active user base to recommend the service.

Q. Will you ever have advertising?

J. K. We are pretty clear on this. I mean, would you like advertising on WhatsApp? We wouldn¡¯t. We want messaging to be as simple and easy as possible. We don¡¯t want our application to be a social network or a gaming network, but a messaging network. Your phone itself is very personal to you. You wake up, you look at your phone. You go to sleep, you check your phone. We want to be purely about messaging.

Q. At what times do you see the greatest activity?

B. A. When there are things going on that relate to personal interests like soccer, when there is a big match, for example. So it¡¯s big sporting events and royal weddings, but also world events, great natural disasters or security threats. New Year¡¯s is also a great day for us.

Q. As it used to be for telephone operators. Are you aware of the damage you have done to their business?

J. K. It¡¯s natural evolution in the way people communicate. You can make an argument that SMS replaced calls, which replaced telegraphs, which replaced people delivering messages on horses and carrier pigeons. The human desire to communicate and stay in touch is fundamental to our civilization. We live in a free market and people choose the best way to communicate.

Q. Are we going to see a computer version?

B. A. Our product plans are not something we talk about publicly. A computer is a way to communicate and it¡¯s something we think about. But there¡¯s still not much we can tell you about how it might work.

Q. Will there be a version for the Firefox operating system?

J. K. That is not in our plans, at the moment.

Q. If I change phone, how can I keep my messages?

J. K. If you back up do a full back up to ITunes. All your messages and everything you keep should be there.

Q. What phone do you use?

J. K. A Nexus 4 and a Blackberry.

B. A. A HTC One and a Nokia con a keyboard; I like a keyboard phone and that is getting hard to find.

Q. Where are my messages stored and how secure are they?

B. A. Since we are not an advertising-driven company, our goal is to know as little about the customer as possible. We don¡¯t ask people their gender, their birthday, where they live or what their spending habits are. Once a message has been delivered to a device and acknowledged as successfully delivered, we don¡¯t keep them.

Q. What do the little green check marks mean?

B. A. One means it has been received by our server. The double check mark means it has been delivered to the receiver¡¯s phone. It doesn¡¯t mean it has been read, just delivered.

Q. How much do you compress images?

J. K. Just what¡¯s necessary to strike a balance between speed and quality. If someone wants to send a large image, for storage purposes, then there is email. WhatsApp is for direct communication and not to send 20-mega photos. We use techniques to compress and resize it so you get a good-quality image on your phone.

Q. What do you think of competitors such as Line?

J. K. How can there be a free product; what makes it free? There must be a hidden cost. Something can be free for a time, but not for ever. People realize that the no games-or-gimmick philosophy is a price worth paying.